Since everyones idea is for the match be for WM30,why not build Hunico? He can speak perfect english,has shown to be a great competitor against different styles,a work horse that played the Sin Cara part better then Sin Cara.Also if anyone remembers the Survivor Series match were Cara messed his leg up,he was the only one trying to keep the match going instead of 'Oh he's really hurt lets all stop and stare'. He could use the exposure more then ADR or Cara

but if there replacing rey i think they should go with someone who still has ten years in them.

It could take a while to find someone, send them through developmental to teach them the 'WWE style'. Could take as much as 2 years to do all that.
At least Hunico has a head start and could fill the gap until someone suitable is found, given that Rey's apparently in talks to quit immediately.